Some U.S. officials this year are expected to get smartphones capable of handling classified government documents over cellular networks , according to people involved in the project .

The phones will run a modified version of Google 's Android software , which is being developed as part of an initiative that spans multiple federal agencies and government contractors , these people said .

The smartphones are first being deployed to U.S. soldiers , people familiar with the project said . Later , federal agencies are expected to get phones for sending and receiving government cables while away from their offices , sources said . Eventually , local governments and corporations could give workers phones with similar software .

The Army has been testing touchscreen devices at U.S. bases for nearly two years , said Michael McCarthy , a director for the Army 's Brigade Modernization Command , in a phone interview . About 40 phones were sent to fighters overseas a year ago , and the Army plans to ship 50 more phones and 75 tablets to soldiers abroad in March , he said .

`` We 've had kind of an accelerated approval process , '' McCarthy said . `` This is a hugely significant event . ''

Currently , the United States does n't allow government workers or soldiers to use smartphones for sending classified messages because the devices have not met security certifications .

Officials have said they worry that hackers or rogue apps could tap into the commercial version of Android and spill state secrets to foreign governments or to the Web through a publisher such as WikiLeaks . As many as 5 million Android users may have had their phones compromised by a recent virus outbreak rooted in apps found on Google 's market , said security software maker Symantec .

But with a secure smartphone , a soldier could see fellow infantry on a digital map , or an official could send an important dispatch from Washington 's Metro subway without fear of security breaches .

Developers in the government program have completed a version that has been authorized for storing classified documents but not transmitting them over a cell network , said two people contributing to the initiative . Smartphones cleared for top-secret dispatches -- high-level classified information that would compromise national security if intercepted -- are expected to be ready in the next few months , they said .

Rather than building special handsets hardwired with secure components , the government plans to install its software on commercially available phones , the people familiar with the project said . This approach is far less expensive and allows the government to stay up to date with the latest phones on the market , they said .

Android vs. Apple

There are hundreds of different Android models available , and more than half of all smartphones sold globally in a recent quarter use Android , according to industry research firm Gartner .

Verizon Wireless has sold more Android phones than any other U.S. cell carrier , thanks in part to its marketing emphasis interest on the Droid brand . About a year ago , Verizon also got the iPhone , ending AT&T 's U.S. exclusivity with that device .

`` There 's a lot of interest in Android , '' Bryan Schromsky , a Verizon director for its wireless data services , said in a phone interview . `` We are seeing Android sales across all branches of government . ''

Still , Apple 's iPhone and iPad are also highly desired among U.S. officials , and people involved in the U.S. smartphone program said their goal is to support any type of smartphone . As CNN has reported , the Chairman of the Joint Chiefs of Staff , Gen. Martin Dempsey , uses an iPad to read his classified intelligence by downloading cables and disconnecting from the network .

However , the government chose to work on Android first because Google already allows people to tinker freely with its code , said those working on the project . Federal officials have met with Apple , but they were told they could not have access to the core of the company 's mobile operating system , said Angelos Stavrou , an information-security director at George Mason University who is working on the government project as a contractor , in a phone interview .

`` Android was more cooperative in supporting some of the capabilities that we wanted to support in the operating system , whereas Apple was more averse , '' Stavrou told CNN . `` They 're shifting the strategy now . ''

An Apple spokeswoman declined to comment on the meeting or any changes to its strategy .

Google publishes the source code for Android on its website for anyone to download and modify , and some partners are given access to the code before others . A Google spokesman declined to comment on the government project .

When Google releases a new version of Android or when a new version of its phones comes out , a compatible software update to the government 's secure Android can be ready within two weeks , Stavrou said .

Emphasis on security

Government programmers are making security modifications to Android 's kernel , which is the operating system 's central component , the people involved said . The version will allow users to choose which data from Android and its applications can be sent over the Internet , they said .

`` When you download an application on your phone , you do n't really know what it does , '' Stavrou said . `` We test the application in labs before the user consumes that application . ''

After testing more than 200,000 apps , the researchers discovered that many programs ask for access to far more personal information contained in the phone than they need and , more alarmingly , send some of that superfluous data to the app developers ' servers , Stavrou said .

Even some well-intentioned features can compromise national security if left unchecked . For example , a weather app may automatically send a phone 's GPS coordinates over the Internet to deliver a local forecast , or games may send the device 's unique identifier along with a high score .

On government phones , officials will be prompted with detailed reports about what data may be sent , and they can decline or allow each transmission , the people involved said .

`` People want to play ` Angry Birds , ' and we do want our people to be able to download ` Angry Birds , ' '' Stavrou said . But he added , `` If a clock application gets your GPS and transmits something over the network , that 's not something that we would want to support . ''

Stavrou , along with seven others at George Mason and the National Institute of Standards and Technology , are developing the smartphone software . They are also consulting with several federal agencies , many within the Department of Defense , he said . He declined to name them .

`` The government is actually working pretty hard in getting this technology to most agencies , '' Stavrou said . `` Security is everybody 's concern . ''

A secret project

Officials have not spoken in depth about the project until now . Reuters and some trade publications , including Government Computer News and FedTech Magazine , have previously reported some details .

`` We are very cautious about what we release to the public , '' Stavrou said . `` The details of the technology have been something that we have not publicly disclosed . ''

The project is funded by the Defense Advanced Research Projects Agency , the group responsible for early development of GPS and the Internet , Stavrou said . The Defense Department , which houses the agency , has designated the smartphone project as a priority , he said .

The National Security Agency has been designated with evaluating the smartphone software for certification , Stavrou said . The NSA gave approval for an earlier version of the system to handle classified data stored on a device , he said .

The NSA is also working on a competing system called SE Android , or Security Enhanced Android , Stephen Smalley , a National Security Agency official , wrote this month in a brief e-mail to a group of software developers that was obtained by CNN . SE Android is less flexible in supporting new devices or Android updates from Google and is unlikely to be deployed widely , Stavrou said .

An NSA spokeswoman wrote in an e-mail , `` The ultimate goal is to give war fighters , analysts and other intelligence professionals access to classified information on the go -- boosting innovation in the field , efficiency and productivity . ''

In an unusual move for the federal government , each version of the secure Android operating systems will only need to be certified once before it can be deployed to any U.S. agency , said two people involved in the project . Typically , each agency does its own independent security testing , they said .

Also atypical is that the NSA published the source code for SE Android online . The same will be done with the Defense Advanced Research Projects Agency-funded project . Standardization group OpenSSL Software Foundation is helping with security compliance , said Steve Marquess , a co-founder for the company .

The NSA 's Smalley announced the first release of SE Android with a two-sentence message two-sentence message on January 6 to a developer mailing list . He concluded by saying , `` Enjoy ! ''

`` We had to go through many hoops for that to happen , '' Stavrou said of the plan to open-source the software . `` By handing the source code out , other people will be able to take a look and tell us about bugs . ''

Private interest

Many companies have expressed interest in the government smartphone project , officials said . The corporations that were among the first to adopt the BlackBerry are interested in Android , said Verizon 's Schromsky . The Apple spokeswoman also noted that nearly all Fortune 500 companies are testing or have employees using iPhones and iPads .

Another obstacle for the government will be to figure out how to secure voice calls , Schromsky said .

`` Voice is the immediate need , '' Schromsky said . `` These devices are awesome . They can do so many things , but at the end of the day , I still need to make a voice call . ''

After the Defense Advanced Research Projects Agency project is certified for classified data , developers plan to work on securing the Android system for voice-over IP communications using apps such as Skype , Stavrou said .

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Government , military officials to get Android phones capable of sharing secret documents

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The phones will run a modified version of Google 's Android software , sources say

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Contractor : Google `` more cooperative '' than Apple working with government on phones